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Difference between getCurrentSession() and openSession() in hibernate.

Fri, 25 Jul 2008 02:32:00 GMT

原文来自： http://www.techfaq360.com/viewFreshers.jsp?tutorialId=840
getCurrentSession() :
The "current session" refers to a hibernate Session bound by hibernate behind the scenes, to the transaction scope.
A Session is opened when getCurrentSession() is called for the first time and closed when the transaction ends.
It is also flushed automatically before the transaction commits. You can call getCurrentSession() as often and anywhere you want as long as the transaction runs.
To enable this strategy in your hibernate configuration:

set hibernate.transaction.manager_lookup_class to a lookup strategy for your JEE container
set hibernate.transaction.factory_class to org.hibernate.transaction.JTATransactionFactory

Only the Session that you obtained with sf.getCurrentSession() is flushed and closed automatically.

Example :
try {
UserTransaction tx = (UserTransaction)new InitialContext()
.lookup("java:comp/UserTransaction");

tx.begin();

// Do some work
sf.getCurrentSession().createQuery(...);
sf.getCurrentSession().persist(...);

tx.commit();
}
catch (RuntimeException e) {
tx.rollback();
throw e; // or display error message
}

openSession() :
If you decide to use manage the Session yourself the go for sf.openSession() , you have to flush() and close() it.
It does not flush and close() automatically.
Example :
UserTransaction tx = (UserTransaction)new InitialContext()
.lookup("java:comp/UserTransaction");

Session session = factory.openSession();

try {
tx.begin();

// Do some work
session.createQuery(...);
session.persist(...);

session.flush(); // Extra work you need to do

tx.commit();
}
catch (RuntimeException e) {
tx.rollback();
throw e; // or display error message
}
finally {
session.close(); // Extra work you need to do
}

104人力银行 2008-07-25 10:32 发表评论

struts2 for eclipse plugin下载 (eclipse struts2插件下载)

Fri, 30 May 2008 07:18:00 GMT

eclipse struts2插件下载

104人力银行 2008-05-30 15:18 发表评论

appfuse1.8.0安装app_user.enabled data type (1111, ‘bit’) not recognized and will be ignored错误解决办法

Thu, 26 Oct 2006 06:15:00 GMT

（转载）这个是DBunit的问题，1.8以上的版本才有这个问题！

只要修改User.java

/**
     * @return Returns the enabled.
     * @hibernate.property column="enabled"
     */
    public Boolean getEnabled() {
        // isEnabled doesnt' work for copying properties to Struts ActionForms
        return enabled;
    }

修改成

/**
     * @return Returns the enabled.
     * @hibernate.property column="enabled" type="yes_no"
     */
    public Boolean getEnabled() {
        // isEnabled doesnt' work for copying properties to Struts ActionForms
        return enabled;
    }

就加了这一点，就可以了，

其实 type="yes_no" hibernate会映射成CHAR(1) , 而type="boolean" 它会映射成BIT , 估计dbunit在插入sample-data.xml的时候会出错。

104人力银行 2006-10-26 14:15 发表评论

struts重复提交

Tue, 09 May 2006 10:14:00 GMT

      解决这个问题有好几种办法，我下面举出一种用Token解决的办法，希望大家把自己的解决办法发表出来，用Token解决需要注意几点，一点首先程序的入口应该是一个action,而不是jsp,这个action的作用就是生成token，然后转向jsp页面，然后这个jsp页面里面的提交按钮会提交到另外一个action,这个action获得表单里面的数据，然后判断是不是重复提交#isTokenValid(request,true)。如果为true执行数据库方面的操作。false是表单重复提交，执行其它操作。
      InitInsertAction.java
            //生成同步令牌避免表单重复提交
      saveToken(request);
      return mapping.findForward(IConstants.SUCCESS_KEY);

      InsertAction.java

      NewsModel newsModel = new NewsModel();
     //对象反射机制
     BeanUtils.copyProperties(newsModel,newsForm);
     newsModel.setNewsPublishTime(DateUtil.getCurrentTime());
     newsModel.setNewsKind(newsForm.getNewsKind());
     newsModel.setNewsContent(content);
     //图片文件路径
     if(imageFile!=null&&!imageFile.equals("")){
      newsModel.setImagePath("/UploadFiles/"+imageFile);
     }
     //小图片文件路径
     /**if(iconFile!=null&&!iconFile.equals("")){
      newsModel.setIconPath("/UploadFiles/"+iconFile);
     }*/
     //数据库方面的处理#插入一条新闻
     INewsDao newsDao = new JdbcNewsDaoImpl(con);
     newsDao.insertNews(newsModel);
    }else{
     //表单重复提交
     if(log.isDebugEnabled()){
      log.debug("表单重复提交");
     }
    }

104人力银行 2006-05-09 18:14 发表评论